The present invention relates to movable electric machinery, and, more particularly, to a power grid connected to movable electric machinery.
Heavy mining machinery used in surface mining and underground “hard rock” mining is typically powered by diesel engines. There has long been a need to reduce the health risks associated with operating such diesel engines in confined surface and underground mining applications. Specifically, diesel engines emit particulate matter harmful to humans, create high noise levels, and add significantly to the “heat loading” in an underground mine. Additionally, the high cost of diesel fuel and diesel engine maintenance present additional downsides.
Conventional overhead grid powered systems, such as rail transportation systems, use pantographs that slide on an overhead wire. These systems require the use of rail based guidance to keep the movable machine (locomotive) within an acceptable proximity to the overhead wires (conductors). Pantograph systems have been attempted to be implemented with haul trucks, but such pantograph systems do not include any “switching” means to switch the direction of travel along the roadway or rail other than lowering the pantograph, going back on diesel power to make the turn, and then re-engaging the pantograph to get back on overhead power.